Saga, the over 50s insurance to holidays group, fired the starting gun for a £3billion stock market flotation today - the biggest public offer of shares since the Royal Mail privatisation.

Members of the public will be able to apply for a minimum of £1,000 of shares in the company, although customers and staff will be given priority and will also be entitled to one free share for every 20 they acquire. Eligible customers who want to apply for the offering need to register on the firm's website today.

Private equity owned Saga has already canvassed its round 2.5 million customers and found that around 700,000 would be interested in buying shares in the company.

Saga Sapphire: The over-50's group offers services ranging from cruises and holidays, home and motor insurance, savings and share dealing

It also launched a TV advertising campaign his month to drum up interest and has taken out adverts in newspapers.

The move will be the biggest shares sell-off since the controversial sale of the Royal Mail by the British government last October, when more than 700,000 people applied for shares in a flotation that initially valued the delivery firm at £3.3billion.

The Saga flotation will also represent a big pay day for an estimated 6,000 current and former employees of Saga and its sister business the AA.

They own about 13 per cent of the business, with executive chairman Andrew Goodsell having a 7 per cent holding.

Customers first: Saga boss Andrew Goodsell said: 'Our customers are at the heart of our brand and I am delighted that they will have an opportunity to become shareholders in the company and to be part of the next stage of our journey.'

Saga, which started as an out-of-season holiday provider in 1950, now offers services ranging from cruises and holidays, home and motor insurance, savings and share dealing through to the UK's best-selling Saga Magazine.

Goodsell said: ‘What began 60 years ago in a small hotel in Folkestone is today one of Britain's most trusted and respected companies. This is in huge part due to the hard work and dedication of our employees.

‘Our customers are at the heart of our brand and I am delighted that they will have an opportunity to become shareholders in the company and to be part of the next stage of our journey.’

Proceeds of around £550million from the float will be used to reduce debt to around £700 million, while existing shareholders will sell a proportion of their holdings.

Expectations for a flotation were raised last week after Saga’s current owners, private equity houses Permira, Charterhouse and CVC Capital. completed a crucial £1.25billion debt refinancing, extending the terms of their loans as well as securing lower interest rates.

Insiders had described that move as ‘the last piece of the jigsaw’.

The Saga float continues the flood of new companies which have, or are seeking to list on the London Stock Markets this year.

Earlier this week, discount shoe chain Shoe Zone announced plans to float on London's AIM market, home to junior firms, in a move that will value the business at around £100million.

Last week, private equity-backed Card Factory also announced it was looking to tap into the appetite for stock market floats.

These are the latest in a string of flotations in the retail sector in recent months, which have included Pets at Home and discount store Poundland. indicating growing confidence on the high street.